I re-tubed my Atomic Reactor 18w 1x12 practice amp a month ago and haven't been thrilled with the tone. I thought maybe with some fine tuning of my modeler settings I'd get my tone back. No luck. Today, I got a little suspicious and pulled the back off. I specifically asked for JJ EL84's but instead they slipped in RUBY TUBES. I called the amp shop and they offered to correct it for free but tried making the case of why I should keep the Ruby's. Ultimately if the amp doesn't sound good to me, that's all that matters but I would like to know if anyone has had good experiences with these tubes in a different application. The amp shop tech swears by them.